#define  _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int i = 0;
	int n = 0;
	int z = 1;
	scanf("%d", &n);
	for (i = 1; i < n + 1;i++)
		{
			z = z * i;
	    }
	printf("z=%d\n", z);
	return 0;
}